This NIH SBIR program intends to ultimately convert high quality colloidal nanocrystals, mainly semiconductor nanocrystals and with some concerns on noble metal nanocrystals, to standard bio-medical reagents. This program is based on our patent-pending technologies for ligand chemistry and bio-conjugation chemistry for colloidal nanocrystals. Colloidal nanocrystals are nanometer-sized fragments of corresponding bulk crystals, which are typically synthesized and manipulated in solution. Their strong size dependent properties and flexible solution-phase processability make them as ideal candidates for many bio-medical applications, such as bio-medical labeling tags, drug delivery carriers, MRI enhancing reagents, etc. The two key challenges for such applications are the commercial scale production of high quality nanocrystals and their reliable bio-conjugation chemistry. The first issue is being addressed by two NSF SBIR programs in this company. This NIH SBIR program will address the second issue, bio-conjugation chemistry. The success of this program will provide academic and industrial scientists/engineers as well as medical workers stable, reliable, inexpensive and simple means to apply high quality nanocrystals in their research, development and other daily duties. This goal will be accomplished by design and development of three complementary series of ligand chemistry and bio-conjugation chemistry kits for the bio-medical applications of colloidal nanocrystals. [unreadable] [unreadable]